[Stu038]

The same broadcast signals are everywhere on the network so in in theory you can split and split to your hearts content. The problem is that every time you fit a splitter you insert aprox 3.5dBmV of loss onto that feed.

From what your saying the feed that you've got into your modem has already been split elsewhere so is border line. There's nothing that you can do about that, though a service tech should be able to increase the levels into the property and reset everything.

The additional F connectors that are sticking out of the wall box are most likely filtered just to allow FM frequencies out for FM hook ups. There was a short period of time though when some areas deployed a splitter with a data leg which connected upto the modem while the other provided all the TV frequencies so you could try connecting your TV card to that.

Thing to watch for is that any messing about you do with cableing and plugging additional equipment in can not only affect your service elsewhere in the house but also the service of your neighbours, all of which could end up being billable back to you if the problems are proven to relate back to "unofficial" work that you've carried out.